diff --git a/gns3server/handlers/api/hypervisor/notification_handler.py b/gns3server/handlers/api/hypervisor/notification_handler.py
index 091858265..a7a8b7f83 100644
--- a/gns3server/handlers/api/hypervisor/notification_handler.py
+++ b/gns3server/handlers/api/hypervisor/notification_handler.py
@@ -38,4 +38,3 @@ class NotificationHandler:
                 notif = yield from queue.get_json(5)
                 ws.send_str(notif)
         return ws
-
diff --git a/gns3server/hypervisor/notification_manager.py b/gns3server/hypervisor/notification_manager.py
index ba65f5b4d..dbe1cff06 100644
--- a/gns3server/hypervisor/notification_manager.py
+++ b/gns3server/hypervisor/notification_manager.py
@@ -25,6 +25,7 @@ class NotificationQueue(asyncio.Queue):
     """
     Queue returned by the notification manager.
     """
+
     def __init__(self):
         super().__init__()
         self._first = True
diff --git a/tests/handlers/api/base.py b/tests/handlers/api/base.py
index 09d52325f..caa96bffb 100644
--- a/tests/handlers/api/base.py
+++ b/tests/handlers/api/base.py
@@ -68,6 +68,7 @@ class Query:
         Return a websocket connected to the path
         """
         self._session = aiohttp.ClientSession()
+
         @asyncio.coroutine
         def go_request(future):
             response = yield from self._session.ws_connect(self.get_url(path))
diff --git a/tests/hypervisor/qemu/test_qemu_vm.py b/tests/hypervisor/qemu/test_qemu_vm.py
index 344c9d8f8..936dac0cd 100644
--- a/tests/hypervisor/qemu/test_qemu_vm.py
+++ b/tests/hypervisor/qemu/test_qemu_vm.py
@@ -145,7 +145,7 @@ def test_termination_callback(vm, async_run):
         vm._termination_callback(0)
         assert vm.status == "stopped"
 
-        async_run(queue.get(0)) # Ping
+        async_run(queue.get(0))  #  Ping
 
         (action, event, kwargs) = async_run(queue.get(0))
         assert action == "vm.stopped"
@@ -164,8 +164,7 @@ def test_termination_callback_error(vm, tmpdir, async_run):
         vm._termination_callback(1)
         assert vm.status == "stopped"
 
-
-        async_run(queue.get(0)) # Ping
+        async_run(queue.get(0))  #  Ping
 
         (action, event, kwargs) = queue.get_nowait()
         assert action == "vm.stopped"
diff --git a/tests/hypervisor/test_notification_manager.py b/tests/hypervisor/test_notification_manager.py
index 72b6dfcf4..444bc805e 100644
--- a/tests/hypervisor/test_notification_manager.py
+++ b/tests/hypervisor/test_notification_manager.py
@@ -69,7 +69,6 @@ def test_queue_json_meta(async_run):
     assert len(notifications._listeners) == 0
 
 
-
 def test_queue_ping(async_run):
     """
     If we don't send a message during a long time (0.5 seconds)
diff --git a/tests/hypervisor/test_project.py b/tests/hypervisor/test_project.py
index be4bc0565..c2364cb8b 100644
--- a/tests/hypervisor/test_project.py
+++ b/tests/hypervisor/test_project.py
@@ -262,7 +262,7 @@ def test_list_files(tmpdir, loop):
 def test_emit(async_run):
 
     with NotificationManager.instance().queue() as queue:
-        (action, event, context) = async_run(queue.get(0.5)) # Ping
+        (action, event, context) = async_run(queue.get(0.5))  #  Ping
 
         project = Project(project_id=str(uuid4()))
         project.emit("test", {})
diff --git a/tests/hypervisor/vpcs/test_vpcs_vm.py b/tests/hypervisor/vpcs/test_vpcs_vm.py
index 434b253f5..df0b042fe 100644
--- a/tests/hypervisor/vpcs/test_vpcs_vm.py
+++ b/tests/hypervisor/vpcs/test_vpcs_vm.py
@@ -87,9 +87,8 @@ def test_start(loop, vm, async_run):
     process = MagicMock()
     process.returncode = None
 
-
     with NotificationManager.instance().queue() as queue:
-        async_run(queue.get(0)) # Ping
+        async_run(queue.get(0))  #  Ping
 
         with asyncio_patch("gns3server.hypervisor.vpcs.vpcs_vm.VPCSVM._check_requirements", return_value=True):
             with asyncio_patch("asyncio.create_subprocess_exec", return_value=process) as mock_exec:
@@ -147,7 +146,6 @@ def test_start_0_6_1(loop, vm):
             assert vm.is_running()
 
 
-
 def test_stop(loop, vm, async_run):
     process = MagicMock()
 
@@ -166,7 +164,6 @@ def test_stop(loop, vm, async_run):
                 loop.run_until_complete(asyncio.async(vm.start()))
                 assert vm.is_running()
 
-
                 with asyncio_patch("gns3server.utils.asyncio.wait_for_process_termination"):
                     loop.run_until_complete(asyncio.async(vm.stop()))
                 assert vm.is_running() is False
@@ -176,8 +173,8 @@ def test_stop(loop, vm, async_run):
                 else:
                     process.terminate.assert_called_with()
 
-                async_run(queue.get(0)) # Ping
-                async_run(queue.get(0)) # Started
+                async_run(queue.get(0))  #  Ping
+                async_run(queue.get(0))  #  Started
 
                 (action, event, kwargs) = async_run(queue.get(0))
                 assert action == "vm.stopped"